Experimental Study of Dehumidified Air Convection by Holographic and Thermocouple Methods

Abstract

Abstract Thermal convection of dehumidified air is studied experimentally under conditions close to normal (atmospheric pressure ≍ 740 mm Hg, temperature range T = 0…50 C). The study is based on fundamental experiment, which is focused on the physical aspects of thermoconcentration convection in fluids, undergoing first-order phase transitions of the “gas-liquid” type. The peculiar features of convection, caused by concentration changes of water vapor (as a result of its evaporation or condensation), are discussed in terms of dimensionless parameters. The couple of standard complementary experimental methods are used: holographic interferometry for visualization of convective flows and thermocouple method for heat flux measurements. Test experiments demonstrate and approve the design characteristics of the setup. The observations of convective flows in dehumidified air are demonstrated. Experimental setup is described in all details, including the original design of the cold heat exchanger (resembling a heat tube), proposed for next experiments with humid air.